Comparison of metal-organic chemical vapour deposition TiN thin films with different process cycles

Abstract

As a diffusion barrier layer, metal-organic chemical vapour deposition titanium nitride (TiN) thin films are widely used in IC manufacturing. It is well known that a N 2 /H 2 plasma treatment should be applied to remove highly concentrated impurities such as carbon and oxygen in the as-deposited TiN films. For an efficient plasma treatment, the fabrication process of relatively thick films has to be repeated. In this paper, the electrical performance of different TiN films with single and multiple process cycles is systematically compared to both blanket and patterned wafers. It was found that a multi-cycle process introduces local interfaces, which correspondingly degrades the electrical conductivity of a TiN film. Throughputs of different processes were also compared. The process with a single cycle shows an 18% higher throughput than the process with dual cycles. It is also reported for the first time that the plasma treatment efficiency is position sensitive in real structures.